Black has many pieces attacked and desperately seek counterplay.
13. g4g5 This is the point. White threatens to take on h6 and if Black captures on g5, a dangerous knight will go to this square. 13... f7f5  14. g5h6 Accurate play - Firouzja will give no chance until the end of the game. 14... f5e4  15. f3g5 Another precise move.